For me (so far anyway), deleting something has meant getting rid of it completely. If I take the time to decide to purge something, I don't want to have to spend more time later looking at the backup copy of those supplies to decide (again) if I really want to delete it.
So far, I think I've only actually deleted one kit that I've purchased here, although I've gotten rid of just about everything from my pre-SSD days. There are kits that I'm not sure I'll use, and I know that there will usually be something new that comes along that I'll like and could use in place of something that I get rid of. If I didn't have to buy my supplies, it would be easier to delete things I'm not sure about. However, I will go back and use something that I bought ages ago and I'd rather do that than have to buy a replacement for it.
I've been decluttering my house and I really want to declutter my digi supplies, too. I'm having a hard time committing to actually getting rid of things. Maybe I'll make a "deleted" folder and move things there, then go back next time I purge and look at it. If my experience is anything like just about everyone else's, I'll end up truly deleting those supplies then. At least they'll be off of my working drive until then, though.